Untersuchungen zur Häufigkeit von Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum and Babesia spp. in Ixodes ricinus aus Bayern und Baden-Württemberg

625 adult unfed I. ricinus ticks from three recreational areas
located near Munich and Passau, 275 adult engorged I. ricinus ticks
from dogs of Bavaria and Baden-Württemberg and 25 adult engorged I.
ricinus ticks from cattle of an area in Switzerland, which is
endemic for bovine granulocytic ehrlichiosis, were collected over a
specific period (3/2003-3/2004). The ticks were examined for an
infection with B. burgdorferi sensu lato spp., A. phagocytophilum
and piroplasms by the use of Real-Time PCR and nested PCR. In
addition RFLP analysis and sequencing were chosen for the
differentiation of the species and OspA types of B. burgdorferi
sensu lato. The examination of unfed ticks resulted in a prevalence
of 35,4% for B. burgdorferi sensu lato, 4,5% for A. phagocytophilum
and 1,3% for piroplasms. There was no significant difference for
the infection rates of B. burgdorferi sensu lato between the
different sampling areas, whereas A. phagocytophilum showed a
significantly higher prevalence in one sampling side in Munich and
a significantly lower prevalence in Passau. Apart from infections
with only one pathogen, coinfections with B. burgdorferi sensu lato
and A. phagocytophilum could be detected in 1,1% of the unfed
ticks, with a local cluster in one area in Munich and 0,3% of the
unfed ticks showed a coinfection with B. burgdorferi sensu lato and
piroplasms. Prevalence rates of 8,4%, 4,7% and 5,1% were identified
for B. burgdorferi sensu lato, A. phagocytophilum and piroplasms
respectively in engorged ticks from dogs, 0,7% of these ticks were
coinfected with B. burgdorferi sensu lato and A. phagocytophilum.
The examination of engorged ticks from cattle revealed in a
prevalence rate of 8,0% for B. burgdorferi sensu lato and 60,0% for
A. phagocytophilum. The high infection rate of A. phagocytophilum
probably resulted from an infection of the cattle with this
pathogen. The difference in the prevalence rate of B. burgdorferi
sensu lato in unfed and engorged ticks might be caused by their
distinct geographical origin, the degree of blood uptake and
different factors in the blood of the different host species which
are able to protect the host from being infected with Borrelia. The
differentiation of B. burgdorferi sensu lato into the species and
OspA types showed that the clinically relevant species B. afzelii,
B. burgdorferi sensu stricto and B. garinii, in which B. garinii
was represented by the OspA types 3, 4, 5, 6 and 8 could be
detected. Additionally, B. valaisiana, a species which is suspected
of being pathogenic to humans and the recently described new
Borrelia genospecies, B. spielmanii (previously A14S), were
detected. Alltogether a broad heterogeneity for Borrelia species
and subspecies (classified by OspA types) could be observed in
unfed ticks, above all in one sampling side in Munich. Ticks
engorgd from dogs and cattle showed a less heterogeneous pattern of
distribution.